Question

Here’s an array in Java:

int[] myArray = new int[3];
myArray[0] = 0;
myArray[1] = 1;
myArray[2] = 2;

The first line immediately reserves 3 consecutive blocks of memory. Creating a fourth element would actually require creating a new array with int[4], and then transferring values from index 0 to 2 into the new array. Such as the following:

int[] mySecondArray = new int[4];
for (int i = 0; i < myArray.length; i += 1) {
    mySecondArray[i] = myArray[i];
}
mySecondArray[3] = 3;

But in PHP, we can declare an array, and simply add another element without all the fuss that a Java requires.

$my_array = array(0, 1, 2);
$my_array[] = 4;

Does PHP actually take care of creating a new array after pushing an additional element onto an existing array? Or are PHP arrays actually not the same (in terms of memory) as arrays in languages such as C and Java? I’m a little concerned, because I see a lot of PHP code that iterates through a loop and appends 50+ new elements onto an existing array, which would be utterly ridiculous to do in Java.

Answer 1

Or are PHP arrays actually not the same (in terms of memory) as arrays in languages such as C and Java?

In PHP arrays are in fact hash tables. However, the memory management is hardly comparable, because they are two completely different languages.